The presence of significant quantities of H.sub.2 S and CO.sub.2 in various "sour" industrial gaseous streams poses a persistent problem. Although various procedures have been developed to remove and recover these contaminants, most such processes are deficient, for a variety of reasons.
In one cyclic method currently attracting attention, the sour gas is contacted with an aqueous solvent-reactant system, which comprises a regenerable reactant, to produce solid free sulfur which is recovered either prior to or subsequent to regeneration. Suitable reactant materials include polyvalent metallic ions, such as iron, vanadium, copper, manganese, and nickel, and include polyvalent metal chelates. Preferred reactants are coordination complexes in which the polyvalent metals form chelates with specified organic acids.
A problem associated with such processes is that the chelates decompose or degrade significantly over time, requiring replacement thereof and removal of the degradation products. Since the chelates are costly materials, the economics of such processes are directly affected by the extent of decomposition of these materials. A process which either prevented such degradation or provided an alternative inexpensive reactant composition might have great utility.